/**
 * 48. 旋转图像
 *
 * 给定一个 n × n 的二维矩阵 matrix 表示一个图像。请你将图像顺时针旋转 90 度。
 * 你必须在 原地 旋转图像，这意味着你需要直接修改输入的二维矩阵。请不要 使用另一个矩阵来旋转图像。
 *
 * 示例 1：见图T48-1
 * 输入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
 * 输出：[[7,4,1],[8,5,2],[9,6,3]]
 *
 * 示例 2：见图T48-2
 * 输入：matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
 * 输出：[[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]
 *
 * 示例 3：
 * 输入：matrix = [[1]]
 * 输出：[[1]]
 *
 * 示例 4：
 * 输入：matrix = [[1,2],[3,4]]
 * 输出：[[3,1],[4,2]]
 *
 * 提示：
 * matrix.length == n
 * matrix[i].length == n
 * 1 <= n <= 20
 * -1000 <= matrix[i][j] <= 1000
 *
 * 来源：力扣（LeetCode）
 * 链接：https://leetcode-cn.com/problems/rotate-image
 * 著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。
 *
 */
package zw;

public class T48 {
	public void rotate(int[][] matrix) {
		int temp = 0;
		int size = matrix.length;
		int nextX = 0;
		int nextY = 0;
		int currentX = 0;
		int currentY = 0;
		for(int i = 0; i < (size+1) / 2; i++) {
			for(int j = i; j < size-i-1; j++) {
				currentX = i;
				currentY = j;
				
				nextX = currentY;
				nextY = size-1-currentX;
				temp = matrix[nextX][nextY];
				matrix[nextX][nextY] = matrix[currentX][currentY];
				currentX = nextX;
				currentY = nextY;
				for(int k = 0; k < 4; k++) {
					nextX = currentY;
					nextY = size-1-currentX;
					int temp2 = matrix[nextX][nextY];
					matrix[nextX][nextY] = temp;
					temp = temp2;
					currentX = nextX;
					currentY = nextY;
				}
			}
		}
    }
	
	public static void main(String[] args) {
		T48 t48 = new T48();
//		int[][] matrix = new int[][] {{5,1,9,11},{2,4,8,10},{13,3,6,7},{15,14,12,16}};
//		int[][] matrix = new int[][] {{1,2,3},{4,5,6},{7,8,9}};
		int[][] matrix = new int[][] {{1,2},{3,4}};
		t48.rotate(matrix);
		for(int i = 0; i < matrix.length; i++) {
			System.out.print("[");
			for(int j = 0; j < matrix.length; j++) {
				System.out.print(matrix[i][j] + ", ");
			}
			System.out.print("]");
		}
	}
}
